Process of recovering tin or tin and lead.



?ATENTED MAR. 6, 1906.

J. G. TALIAFERRO. PROCESS OF REGOVBRING TIN 0R TIN AND LEAD.

fiPPI-IUATIOE PXLED KARZT. 1985 mvewro {w} ATTORNEYS UNITED STATES JOHNC.

PATENT OFFICE.

TALIAFERRO, OF BALTIMORE, MARYLAND, ASSIGNOR TO CONTI- RENTAL CANCOMPANY,- OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

PROCESS OF REOOVERING TIN OR TIN AND LEAD.

Specification of Letters Patent.

Patented March 6, 1906.

Application filed Karol: 27, 1905. Serial Bot 252,843.

To all whom it may concern.-

Be it known that 1, JOHN C. TALIAFERBO, a citizenof the United States,residing at Baltimore, State of Maryland, have invented a new and usefulImprovement in the Processes of Recovering Tin or Tin and Lead, of whichthe following is a specification.

In the accompanying drawings, which make part of this specification,Figure l-is a front elevation, and Fig. 2 a cross-section, of a furnacesuitable for fusing the tin in the mixture; and Fig. 3 shows in verticalsection a suitable charcoal-furnace for treating the skimmings.

The purpose of my invention, generally stated, is the separation of tinor tin and lead from a mixture of iron or steel.

The process is peculiarly applicable to the recovery of tin or tin andcad from the mixture of these metals which has been recovered from ironor steel sheets or articles made from iron or steel sheets.

The metallic tin which has been removed from tin-scrap by theelectrolytic'process of detinning or by like rocesses is largelyamalgamated with the slieet metal or other base which has been coatedwith tin. Heretofore it has not been practicable to use the tin re-.

moved from scrap-tin, as above stated, for the purpose of makin solder,which is'a mixture of tin and lead a one and which requires to be free,or substantially so, from the presence of iron or other deleteriousmetal, and for that reason great loss has been sustained by theproducers of detinned plate, because the tin owder produced therebycould not he satis actorily refined into pure metallic tin suitable formaking solder, but could only be used for textile work or other useswhen it has a much less commercial value than the pure pi -tin ofcommerce. My invention removes t is objectionable feature entirely andrestores the pig-tin recovered by the detinning age 0 or othercommercial solder, greatly to its value.

The roblem to be solved is how to get rid of the iron or steel. Thespecific gravity of iron and steel does not vary sufficiently from thatof tin to effect a separation based on specific avity. The fusing-pointof iron and steel is, however, some 2,500 higher than iron) to puremetallic tin free from iron thereby adding the fusing-point of tin. Thisfact I utilize and fuse the tin, leaving the iron in suspension thereinbut unfused. I then effect a me chanical stratification by adding enou hlead to unite with the fused tin, so that t is iron will float to thetop of the mixture, where it can be skimmed off. As these skiminingswill contain a certain amount of tin and lead, I preferably carry outthe process by a further refinement in treating these skimmings torecover the tin or lead. This effects a still further saving; but themain process is quite independent of this subsequent step. When I do,however, save the tin or lead in the skimlnings, I take said skimmingsto a charcoalfurnace and fuse the tin or lead therein, which tricklesdown through the charcoal, while the igoi remains upon the top of thecharcoal Obviously my invention can be carried out in a variety of waysand by a variety of structures and the essence of it is as above setforth, and the apparatus described is'purely illustrative.

1 represents any ordinary furnace having a bed 2 and a tap 3. Into thisfurnace is charged the mixture designed to be purified. The urnace israised to a temperature high enough to fuse the tin, but leaving theiron in suspension throughout the fused tin. Lead might be added in thefurnace; but for convenience I prefer to tap the mixture out into anysuitab e vessel, where it is still kept molten, and there add asufficient percentage of lead as shall by uniting with the tin acuire asufficient specific gravity to sink to t e bottom of the vessel andfloat the iron to the top. The iron can readily then be removed byskimming.

In order to save the tin and lead inadvertently caught up in theskimmings, the latter are taken to the charcoal-furnace. (Seen in Thisis an ordinary upri ht furnace proper pro ortions of tin and lead if notso already an a fine well-refined article of commercial solder is theresult.

Having described my invention, I claim- 1. The process of separating tinor tin and lead from iron or steel which consists in fusing the tin ortin and lead, adding suflicient lead to float the iron or steel to thetop of the mixture and mechanically removing the alloy.

2. The process of se arating tin or tin and lead from iron or stee whichconsists in fusing thetin or tin and lead, adding sufficient lead tofloat the iron or steel to the top of the mixture and skimming off theiron or steel.

, 3. The process of separating tin or tin and lead from iron or steelwhich consists in fusing the tin or tin and lead, adding sufficient leadto float the iron or steel to the top of the mixture, skimming ofi theiron or steel and separating the tin and load from the iron or JOHN G.TALIAFERRO.

Witnesses:

B. H. LARKIN, BLANOHE A. OULD

